Investigations will be continued on the mechanism of action of ethanolamine ammonia-lyase, a B12-dependent enzyme. The reactions undergone by the coenzyme and substrate during the course of the catalytic process will be studied by ESR and NMR spectroscopy. Analogs of the substrate will be tested for their effect on the enzyme-coenzyme complex. The interaction between enzyme and omega-adenylalkyl cobalamins will be studied to test the hypothesis that the enzyme facilitates the rupture of the coenzyme at the carbon-cobalt bond by stretching the bond. Finally, studies will be initiated on the structure of the enzyme.